Lamb Engineering Norton Rotary Motorcycle
Jaw-dropping power plants are the ultimate party piece for a custom motorcycle build. Visually impactful engines like Suzuki’s Ram-Air 550, Fabio Taglioni’s 90-degree desmo twin or Harley’s robust Knucklehead add depth and mechanical marvel to a build, reminding us that it’s all about the connection between man and machine. But if you really want to rattle the cage, abandon pistons altogether, because after all, there’s more than one way to combust fuel and air.

By day, Larry Houghton runs a successful engineering firm in Salisbury, England, but he’s recently retired to devote more time to his passions, predominantly two-wheeled ones. With time on his side, and free rein over the equipment at his company, he could finally pursue a project he’d shelved in the back of his mind for years.

Lamb Engineering Norton Rotary Motorcycle
Larry had once happened upon a Norton rotary motorcycle engine at a swap meet and remarked on its wild space-age appearance. 15 years later, he heard the unmistakable howl of the twin-rotor Wankel outside a pub and the search for a suitable donor started in earnest.

Built in fairly limited numbers, rotary-powered Norton motorcycles don’t turn up every day, but Larry was able to track one down on eBay and secured it with a cheeky offer. The once-loved ’88 Interpol 2 had covered 64,000 miles before being put into storage for 20 years. Larry’s pal Lee is also a rotary enthusiast, and he returned the Interpol to running condition in short order. Despite the odometer readout, the Wankel ran flawlessly, and the duo noted the SE stamping (Service Exchange) in the serial number, indicating that it was a factory-overhauled unit.

Lamb Engineering Norton Rotary Motorcycle
Larry’s initial plan was to source an Aprilia RSV 1000 chassis, as it’s known to house the rotary engine with ease. He even went as far as sourcing a donor before having a change of heart. Marveling at the distinctiveness of the original Norton frame, he decided something more bespoke was in order.

Ironing out his design with CAD, Larry penned a chassis that hangs the engine like the factory did while accommodating contemporary running gear. Both wheels and the front end were lifted from a Ducati 999, and Larry designed his own polished yolks to make it happen. The Aprilia 1000 donated its swingarm, and keen eyes will note that it’s made the switch from shaft to chain drive.

Lamb Engineering Norton Rotary Motorcycle
We’d be left scratching our noggins if Larry hadn’t revealed that a Norton Commando gearbox facilitates the swap, as no part of the four-speed transmission is visible to the naked eye. Taking things a step further, Larry converted the Commando clutch assembly to a hydraulic setup with a slave cylinder of his design.

A pair of induction tubes dominates the bike’s side profile, addressing the unique cooling challenges of the rotary. Norton maximized the 588 cc engine with internal air-cooling to aid the external fins. A ram-air effect was used to draw air through the interior of the rotors before it exited the engine through the pressed-steel chassis and was drawn through the carburettors.

Lamb Engineering Norton Rotary Motorcycle
While hot induction air creates less-than-ideal conditions, it didn’t impact the bike’s street performance in a significant way. Still, it created a unique challenge for Larry’s build.

The tubes on Larry’s bike support the weight of the engine, while also providing the pathway for cooling air to enter and exit the Wankel and be directed to the twin SU 1-1/4″ carburettors. The system is obviously custom from tip to tail, perhaps most notably in the polished plenum assemblies feeding the carbs.

Lamb Engineering Norton Rotary Motorcycle
With the mechanicals sorted, it was onto the bodywork to shape the bike’s new identity as ‘The Comet.’ Larry leaned on a metalworker by the name of Tony Taysom to craft the fuel tank, exhaust, front fender and tail section, each employing aerodynamic trickery reminiscent of the latest in MotoGP.

Other finishing details include upholstery by Jane Haggar and brilliant paintwork by Joeby’s Airbrush Art. While Larry is quick to give credit where credit is due, this Norton simply wouldn’t be the same without all the custom-machined parts from his own Lamb Engineering. The oil tank, foot controls, taillight and headlights that mirror the Wankel’s finned look were all his handiwork.

Lamb Engineering Norton Rotary Motorcycle
A dream long in the making, Larry reports that the riding experience is sublime. “In my opinion, it’s nothing short of amazing. No vibration, completely linear power curve and the most glorious noise this side of Led Zeppelin. It’s surprisingly well balanced with the engine weight so low,” Larry says.

Lamb Engineering Norton Rotary Motorcycle

With purposeful geometry, a healthy mix of go-fast goodies and that space-age mill hanging out in the breeze, Larry’s Norton rotary motorcycle is a fascinating mechanical study. While the names of some project bikes seem like an afterthought, the Comet hits the nail square on the head.

Lamb Engineering | Website | Instagram | Photos by Del Hickey

Lamb Engineering Norton Rotary Motorcycle


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